Tensioning device



" "March"l'6, '1'9432 B; BoGosLowsKY Y Y' Y25514370 TENS IONING DEVICE Filed Dec. 1Q, 1940 I lNvENT R BY :xl7/y 7 ATTORNEY y 'nero .g iii' a DEVICE as surnames, n york, n. r. Applicationceber 10, 19%, Serial No. 369,380 s claims (ci. 24e-45)' This invention relates to tensioning devices used in connection with winding machines, particularly in connection with ball winding machines in which an elastic strand is wound to vform a ball body.

In such machines, it is customary to feed the strand from a spool to a tensioning pulley and thence to the ball. Rotation of the pulley is restrained by a suitable braking means, and as the strand is applied to the ball the strand is tensioned by the braking force applied to the pulley. In the use of devices of this nature, it has been observed that the strand frequently fails to feed fore it reaches the pulley, and when the tension applied by the pulley is added, the strand is frequently stretched beyond its elastic limit and is broken. Even when the strand is not broken the variations in tension which are caused in this manner are undesirable.

' It is an object of this invention to provide a method and apparatus for tensioning a strand which will avoid these objections.

Other objects and advantages of the invention will appear hereinafter.

A preferred embodiment of the invention selected for purposes of illustration is shown in the 'accompanying drawing, in which,

Figure 1 is a semi-diagrammatic view in perspective, and

Figure 2 is a similar view of a portion of a modified form of the device. l Referring to the drawing, the spool i from which the strand is being unwound is mounted for rotation in any suitable manner. I'he strand 2 leads from the spool to a. pair of rollers 3, I, being guided to the rollers by fork 29, thence through an eye 5 to a tensioning pulley l, thence to a second tensioning pulley i, and thence to the ball 8 which is being wound.

It will be understood that the ball may be held between suitable winding heads (not shown) for winding rotation, and that as winding rotation takes place the strand is drawn inthe usual manner from the tensioning pulley 1. The said pulf ley is connected in the usual manner with a brake f drum 9 on which rides a brake band I0 carrying weight il which may be adjusted to apply the desired braking force.

Before passing to the pulley l, the strand is preferably initially tensioned by the pulley e.

, 5 This pulley is connected wtih brake drum i2 on which rides brake band Ai3 carrying weight Id Vwhich may be adjusted to apply the desired braking force. It will be understood, however, that the use' of the two tensioning ulleys 5 and 'i 10- is optional and that a single pull y may be used if desired. When two pulleysare used, the brain-4 ing force applied to the pulley 6 is very slight. The eye 5 is formed in the end of a lever is pivoted at i6, The said lever should preferably. be very light 'and may be counterweighted at il so as to balance freely on the pivot i6. The

lever i5 operates an electric switch (not shown) contained in thebox i8, which said switch may be of any suitable type adapted for easy operation. Several types of switches are available coxnmercially which operate with very slight pressure l and with very slight amplitude'of movement of the operating element, such' as the so-called micro-switch or the well known mercury switches in which the switch terminals are in a tubeI containing mercury, and the circuit is l made or broken by tilting the tube.

The said switchis interposed in an electric cir-. cuit i8 containing the motor 2li which drives the rollers 3, 4 to unwind the strand from the spool i.

In operation, it is intended to maintain a loose loop 2i in the strand at all times between the rollers 3, and the tensioning pulley 6 in order that the strand will not be under any substantial tension'as it passes onto the tensioning pulley.

Since the portion of the strand which forms the loop passes through the eye 5, it will be observed 'that'if the loop is shortened as shown at 22 by winding rotation of the ball, the lever I5 is lifted 40 to close the switch. This causes the motor 20 to \be operated to drive the rollers 3, 4 to feed additional strand from thespool into the loop, thus lengthening the loop. When this occurs, the lever l5 drops, opening the switch to stop the motor.

445 Thus by intermittent operation of the motor the strand is pulled from the 'spool as required and a loose loop is maintained at all times.

It will be observed that any tension which may;

be required to pull the -strand from the spool is provided 'by the motor driven rolls and that the strand is relaxed within the loop portion so that it always reaches the tensioning pulley 6 in subl stantially untensionedcondition, the tension applied by the lever l5 when the same is lifted being so slight as to be negligible. Therefore,the

tensioning of the strand by the tensioning pulley,

form.

In practicing the invention I have observed that the strand sometimes picks up charges of static electricity which cause it to stick to the, rollers 3, 4. It is desirable, therefore, to mount scrapers 23 in position to engage the rollers to peel the strand away from the rollers when this occurs.

In the modification shown in Figure 2, the lever l5 and the switch operated thereby are replaced by a photo-electric cell 25 carried on one of a pair of guide plates 26, 21, between which the loop of the, strand is fed. A beam of light is directed transversely across the space between the guide plates toward the cell as indicated by broken line 28 so that when the loop is shortened suiiciently to cross the beam, the interruption of the beam starts the motor through suitable electrical connections which are well known in the ait.

The motor may be'stopped either by a suitable timing device, or may be stopped by a second interruption of the beam as the loop begins to lengthen.

It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims.

I claim as my invention:

1. In a strand tensioning device, in combination, strand supply means, strand tensioning means, and means for maintaining a loose untensioned loop in the strand between said supply means and said tensioning means, said means including rollers engaging said strand to feed the same from said spool, and means controlled by the position of the bight of said untensioned loop for controlling the operation of said rollers.

2. In a strand tensioning device, in combination, strand supply means, strand tensioning means, and means for maintaining a loose untensioned loop in the strand between said supply means and said tensioning means, said loop-maintaining means including motor driven feed rolls engaging the strand for pulling the strand from the supply means, and a switch for controlling the operationof said feed rolls in accordance with the position of the bight of said untensioned loop.

3. In a strand tensioning device, in combination, strand supply means, strand tensioning means, and means for maintaining a loose loop in the strand between said supply means and said tensioning means, said loop-maintaining means including motor driven feed rolls engaging the strand for pulling the strand from the supply means, and a switch for controlling the operation of said feed rolls in accordance with the position of said loop, said loop-maintaining means also including a scraper for preventing adhesion of the strand to the feed rolls.

4. In a strand tensioning device, in combination, a supply spool carrying the strand, a tensioning pulley, power driven feeding rolls engaging the strand to pull it out from said spool Tor pulleys as/thercase mayvbefwillgalways be unid and maintain a loose untensioned loop between theiolls and said tensioningpulley, and a roll controlling'Y switchroperated-in respome toshortening of said untensioned loop for intermittently energizing said rolls for feeding out the strand from said spool and increasing the length of said loop. f

5. In a strand tensioning device, in combination, a supply spool carrying the strand, a. tensioning pulley, motor driven feeding rolls engaging the strand to pull it out from said spool, said rolls feeding the strand faster than the greatest speed demanded at said tensioning pulley so as to form a loose untensioned loop between the rolls and said tensioning pulley, and means controlled by the position of the bight of said untensioned loop for intermittently starting and stopping said feed rolls.

6. In a strand tensioning device, in combination, a supply spool carrying the strand, a tensioning pulley, motor driven feeding rolls engaging the strand to pull it out from said spool, said rolls feeding the strand faster than the greatest speed demanded at said tensioning pulley so as to form a loose untensioned loop between the rolls and said tensioning pulley, a switch having an arm with an eye through which the strand in said untensioned loop passes, and means controlled by said switch for intermittently energiz- A'ing the motor of the feeding rolls when the loop shortens to a predetermined limit. l

'7. A process for handling elastic filaments comprising pulling an elastic lament from a supply package, which pulling necessitates varying the tension existing within the filament, passing the lament through a first feeding zone and a second feeding zone and permitting the filament to fall into a loop between the feeding zones, per mitting the loop to freely contract as required to remove the tension from the filament passing from the first feeding zone, utilizing the variation in size of the loop to vary the rate of speed at which the filament is released from the first feeding zone to thereby maintain the size of the loop, passing the filament to the second feeding zone while under the substantially zero tension existing in the loop and passing the filament from the second feeding zone to a using operation.

8. An apparatus for handling elastic filaments Vcomprising a variable-speed feeding means for removing filament from a supply source, a second feeding means for passing the filament to a using operation, both said feeding means being positioned so that the filament is sustained in a loop therebetween, and control means actuated through physical contact with the lower extremity of the loop without tensioning theiament in the loop to decrease the rate of speed of the firstnamed feeding means as the'size of the loop increases and to increase the rate of speed of the first-named feeding means as the size of the loop decreases.

i BORIS BOGOSLOWSKY. 

